Flash bulb socket



May 2, 19 1 R. L. PENNOCK, JR, ETAL 2,932,93

. FLASH BULB SOCKET 2 Sheets-Sheet 1 Filed Aug. 21 1958 INVENTORS ROBERTL. PENNOCK,JR.

HAROLD A. SMITH ATTORNEY M 2 1961 R. L. PENNOCK, JR., ErAL 2,932,936

' FLASH BULB SOCKET I Filed Aug. 21, 1958 2 Sheets-Sheet 2 INVENTORSROBERT L.PENNOCK,JR.

HAROLD A. SMITH A T TOR/IE Y Patented May 2, 1 961 FLASH BULB SOCKETRobert L. Pennock, Jr., and Harold 'A. Smith, Denver, 0010., assignorsto Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., acorporation of Delaware Filed Aug. 21, 1958, Ser. No. 756,481

2 Claims. (Cl. 339-33) This invention is concerned with an improvedflash bulb socket and specifically with an improved flash bulb socketadapted to receive either a large or a small base flash bulb wherein itis unnecessary to provide an adapter to accommodate the small base flashbulb.

The large and small base flash bulbs are normally referred to as thebayonet base and the M2 base bulb respectively. The present inventionprovides an improved flash bulb socket which receives either the bayonetor the M2 base flash bulb without the use of a special adapter.Furthermore, this is accomplished without the use of a structure whichmust be adjusted or modified before inserting the M2 base flash bulb. Inother words, the improved flash bulb socket of the present invention isoperative at all times to receive either the bayonetor the M2 flash bulband no adjustments need be made before inserting one or the otherofthese bulbs.

Specifically, the present invention provides an improved flash bulbsocket wherein a stationary bayonet base socket is provided having amoveable M2 base socket positioned within the bayonet base socket andbiased to a forward position by means of a first spring. Anelectrical-contact rod extends through an opening in the M2 base socketand is biased to a forward position by a second spring to makeelectrical contact with the base contact of either the bayonet or M2base flash bulb. Furthermore, the electrical contact rod extends out ofan opening in a housing when a bulb is in position in the socket. Thebulb may then be ejected by pushing on the portion of the contact rodextending out of the housing.

The present invention will be apparent to those skilled in the art uponreference to the following specification, claims, and drawing of which:

Figure l is a side view of the flash bulb socket of this invention,showing portions of the apparatus in section,

Figure 2 is a front view of the apparatus of Figure 1, Figure 3'is aside view similar to Figure 1 having a bayonet base flash bulb inposition in the socket, and Figure 4 is a side view similar to Figure 1having an M-Z flash bulb in position in thesocket;

Referring to Figure 1, this figure-shows a side view 'of a portion ofthe photographic flash gun incorporating the improved flash bulb socketof the present invention.

The reference numeral designates a housing assem bly, preferably formedof a non-conducting material such V flash bulb is positioned. The member10 is mounted on a handle assembly 13, only a portion of which'is shownin Figure 1. This handle assembly '13 contains the tified by thereference numeral 15. This member14 is rigidly attached to the member 10and is arranged to support an adjustable reflector, not shown. Theadjustable reflector contains a tightening means which en- 7 v gagesgroove 15 in member 14-and can be moved along this groove to focus theflash gun.

The reference numeral 16 identifies a first socketmemher which is alsoconstructed of metal and is rigidly attached to the member 14. Thissocket member 16 is of a tubular shape and has an opening 17 which isadapted to receive thebase of a bayonet base flash bulb. The

opening 17 is defined by a reduced diameter portion formed of aplurality of resilient fingers 18 which resiliently hold and makeelectrical contact to the base of the bayonet base flash bulb. Theresilient fingers 18 can be seen more clearly in the front view ofFigure 2 and the 7 socket in Figure 3.

source of voltage, not shown, for energizing the flash bulb and ispreferably constructed ofa metal tomake elcctrical contact with oneterminal of the source of voltage. The opening 11 in housing 10 receivesa metallic member 14 which ispro'vided witha recessed portion iden- Fromthese figures itcan'beseen that when the flash-bu of the openingr 12pro'videdjin housing 1 0. 'll l erefol',e

The first socket member 16 has a second socket member 20 mountedtherein. This second socket member 20 is provided with anaxial opening,and this opening is provided with a larger diameter at the left hand endthereof, this providing a socket opening 21 to receive the base of theM2 base flash bulb. The base of the flash bulb is engaged by a resilientspring 22 which extends into the opening 21 and engages the base of theM2 base flash bulb 23 as shown in Figure 4. The socket 20 and spring 22are preferably constructed of metal.

The second socket member 20 is positioned within the housing 10, andspecifically within the first socket member 16, by means of a spring 25which engages an angular shoulder '26 formed in the second socket member20. The right-hand end of spring ZS-engages a further stop member 27which is rigidly fixed into position with re-- spect to the housing 10and, as with housing 10, member 27 is constructed of an insulatingmaterial. Therefore, spring 25 is effective. to bias the second socketmember 20 to a forward position wherein a shoulder 46 of socket 20engages for reduced angular portion '18. of socket 16, thereby bringingthe M2 opening 21 into alignment with the bayonet base opening 17.

The reference numeral 29 identifies a contact rod assembly which isprovided with a metallic contact tip 30 at the left-hand end thereof.This contact tip 30 extends through an insulating bushing 31 providedwith,

a shoulder 47 which engages the second socket member 20. As shown inFigure 1, the metallic contact tip 30 extends through the bushing 31 andis attached to auxincontact tip 30. The spring 33 likewise engages ametallic insert 35 which is positioned within member 27 and V: makescontact to a bolt 36,'this bolt formingthe second terminal to which thevoltage supply means may be connected.

Therefore, the electrical circuit for the apparatus shown. 7 in Figure 1extends from handle member 13 to a metala lic clip 37 ,by a circuitmeans, not shown, and from clip. 37 to member 14, to the first or secondsocket members i l 16 and 20, respectively. From this point the circuitextendsthrough the flash bulb to the contact tip 30, spring 33, member35, and bolt 36' to theother'terminal of I j the source of voltage.

The improved flash bulb bulbs 19 and 23, respectively,lare insertedinpositionf is in position, the contact rod assembly 29 is moved .to; theright such that the portion 32 thereof extends out' Sakai. shown inFigures 3 l V and 4 wherein the bayonet base and the M2; base flash:

flash bulbs may be ejected from the socket by movement of the rodassembly 29 to the left, thereby forcing the flash bulb out of thesocket.

From theabove description, it can be seen that we have provided a noveldual flash bulb socket which can be used with either a bayonet baseflash bulb or a small M2 base flash bulb. Other modifications of thisinvention will be apparent to those skilled in the art and it isintended that the scope of the present invention be limited solely bythe scope of the appended claims.

We claim as our invention:

'1. In a flash bulb holding assembly, a first tubular metallic memberhaving an end portion with a reduced diameter opening formed ofresilient fingers adapted to resiliently hold and electrically engagethe bayonet portion of a bayonet base flash bulb, a second tubularmetallic socket member movably mounted within said first socket memberand having an opening extending therethrough, said opening being adaptedto receive the base of a small base flash bulb, resilient spring meansmounted on said second socket member adapted to engage and resilientlyhold the base of a small base flash bulb, a stop member formed ofinsulating material and provided with a conductive portion, a firstmetallic coil spring mounted to engage said second socket member and toengage said stop member to thereby bias said second socket member intoengagement with the reduced diameter portion of said first socketmember, to thereby bring said one end of said second socket member inalignment with the reduced diameter opening of said first socket member,and to establish electrical contact between said first and second socketmembers, an elongated metallic rod movably mounted within said firstsocket member and extending through the opening provided within saidsecond socket member, said rod having an insulating portion to insulatesaid rod from said second socket member, said insulating portion havinga shoulder, a second metallic coil spring mounted to engage saidconductive portion of said stop member and to engage said rod toelectrically connect said conductive portion to said rod and to biassaid shoulder to engage said second socket member such that a contactend of said rod is positioned in alignment with the large diameteropening in said second socket and the reduced diameter opening of saidfirst socket member to thereby make electrical contact to the baseterminal of the flash bulb inserted in said first or second socketmembers, eject means including said rod operable to eject bulbs fromsaid first and second socket members, and means adapted to be connectedto a source of voltage connected to said first tubular socket member andto said conductive portion of said stop member. 1 7 Q 2. In a flash bulbholding assembly, a first tubular metallic member having an end portionwith a reduced diameter opening formed of resilient fingers adapted toresiliently hold and electrically engage the bayonet portion of abayonet base flash bulb, a second tubular metallic socket member movablymounted within said first socket member and having an opening extendingtherethrough, said opening being adapted to receive the base of a smallbase flash bulb, resilient spring means mounted on said second socketmember adapted to engage and resiliently hold the base of a small baseflash bulb, a stop member formed of insulating material and providedwith an opening extending therethrough, a hollow metallic insert mountedwithin the opening in said stop member, a first metallic coil springmounted to engage a shoulder on said second socket member and to engagesaid stop member to thereby bias said second socket member intoengagement with the reduced diameter portion of said first socketmember, to thereby bring said one end of said second socket member inalignment with the reduced diameter. opening of said first socket mem'her, and to establish electrical contact between said first and secondsocket members, an elongated metallic rod movably mounted within saidfirst socket member and extending through the opening provided withinsaid second socket member and the opening provided in said stop member,an insulating sleeve mounted on said rod and insulating said rod fromsaid second socket member, ,a shoulder formed on said sleeve, a secondmetallic coil spring mounted to engage said metallic insert and toengage said insulating sleeve and said rod to electrically connect saidmetallic insert to said rod and to bias said shoulder to engage saidsecond socket member such that a contact end of said rod is positionedin alignment with the large diameter opening in said second socket andthe reduced diameter opening of said first socket member to thereby makeelectrical contact to the base terminal of the flash bulb inserted insaid first or second socket members, eject means including an extensionof said rod operable to eject bulbs from said first and second socketmembers, and means adapted to be connected to a source of voltageconnected to said first tubular socket member and to said metallicinsert.

References Cited in the file of this patent UNITED STATES PATENTS2,343,552 Hollister Mar. 7, 1944 2,565,492 French Aug. 28, 19512,712,117 Stinson June 28, 1955 2,848,701 McKee et al Aug. 19, 19582,920,301 Kawate Jan. 5, 1960 FOREIGN PATENTS 931,147 Germany Aug. 1,1955

